In the manufacture of cigarettes, it is necessary to separate the actual leaf material from the ribs. The leaf tobacco is then processed separately from the ribs and supplied to the cigarette machines. However, the separate rib material can be re-supplied as filler to the tobacco supplied to the cigarette machine, provided the ribs have been suitably processed beforehand. A suitable processing step involves rolling the ribs prior to cutting.
DE 26 57 550 C2 discloses manufacturing a filler for cigarette and pipe tobacco, by cutting the ribs in the unworked state, transversely to the fibre direction, directly after a first setting of the moisture content. Following an intermediate storage, a second cutting step reduces the ribs to the required particle size for the filler. This publication discloses in principle, achieving the prospect of a large expansion of the cut rib material by the ribs being cut transversely to their longitudinal direction. A device for aligning the ribs is not disclosed.
German Offenlegungsschrift 34 08 269 discloses an appliance for aligning tobacco material by means of a vibratory conveyor equipped with partitions. In the area of the vibratory conveyor, baffle plates are only disposed in the initial area of the vibratory conveyor. The alignment of the tobacco rib flow can thereby already be re-suspended in the compression area of the press conveyor, in particular, if a pile-up should occur. The level is regulated by means of a simple, stationary stripper.
In DE 29 03 563 A1 and GB Patent Specification 1 196 166, appliances are described which enable tobacco ribs to be aligned. German Offenlegunsschrift 29 03 563 uses a vibratory conveyor. GB Patent Specification 1 196 166 guides the tobacco ribs through a fall shaft along a baffle, which shaft is equipped with sawtooth-like projections, fall ducts and a vibrator. In both cases, the object is an alignment of the tobacco ribs prior to introduction into a cutting tool, which executes a cross-splitting according to GB Patent Specification 1 196 166. The device disclosed in DE 29 03 563 A1 uses only one vibratory conveyor for the alignment of tobacco ribs and relies upon the effect of vibration movements to produce a high proportion of long fibred rib material. However, it expressly does not claim aligning all ribs identically. It has not partitions, nor does it have a level-regulating device.
Due to their low height, the sawtooth-like projections in a fall shaft of GB Patent Specification 1 196 166 allow only a correspondingly low throughput. Moreover, in the event of a pile-up, a disorientation of the already sorted tobacco ribs can result. This appliance also does not have a device for regulating the level of the tobacco flow.
German Patent Specification 26 23 497 relates to an appliance for aligning tobacco leaves, not tobacco ribs. The ribs are must more bulky, and thus, more difficult to handle, and must be cut in a precisely defined direction, namely in the transverse direction. Otherwise, the ribs display unfavorable expansion behavior, and further working with the cut tobacco is more difficult. The conveyor belts function as partitions, and exhibit an interval related to tobacco leaves. The alignment of the tobacco leaves is effected by the side walls exerting pressure upon the tobacco leaves. A level-regulating device is not provided.
Two other publications, German Offenlegungsschrift 27 42 857 and U.S. Pat. No. 2,732,928, disclose regulating the level of a tobacco flow in the catchment area of a press conveyor. The regulation is effected, in the case of German Offenlegungsschrift 27 42 857, by a conveyor worm. In U.S. Pat. No. 2,732,928, the regulation is effected by a feed hopper having a doctor blade.
New studies have shown that a cut of the ribs in the longitudinal direction, compared with a cut in the transverse direction, incorporates less favorable characteristics in relation to the expansion behavior, to the further working of the rib material with the cut tobacco and to the presence of longer components in a finished cigarette. Due to the automatic orientation of the rib material in the case of a vibratory conveyor of the type specified in German Patent Specification 29 03 563, this device is ruled out for a cross-cutting of rib material.